Intake and total and partial apparent nutrients digestibilities in bulls fed diets containing different concentrate levels

It was aimed to study the intake and total and partial nutrients digestibilities in bovine. It were used five 165 kg growing Nelore bulls, rumen, abomasum and ileum fistulated. A randomized blocks design with four treatments and five collection periods was used. The treatments consisted of four concentrate levels (20, 40, 60 and 80%). The roughage used was Tifton 85' Bermuda grass hay (Cynodon dactylon (L.) Pers.). The NDF and ADF intakes only presented linear reduction with the increase of the concentrate level in the diet. DM and TND intakes were, in average, of 3:45 and 2.24 kg/day, respectively. The DM, OM and TCHO apparent digestibilities increased linearly, in function of the concentrate level in the diet. CP and EE apparent digestibilities presented averages of 59.50 and 70.81%, respectively. There was a linear reduction in the NDF and ADF digestibilities. The concentrate level did not influence the CP and EE ruminal digestion, with averages of 4.80 and 1.41%, respectively. The NDF ruminal digestibility showed linear reduction as the the concentrate level in the diet increased. In the small intestine, the maximum DM digestibility of 34.89% were estimated with 49.01% of concentrate in the diet, OM digestibility linearly increased and CP, NDF, EE and TCHO digestibilities were not influenced by the concentrate inclusion in the diet. There was not effect of the concentrate levels on the DM, OM, CP, EE and TCHO digestibilities in the large intestine, and your averages were 17.98, 12.48, 10.53, -2.84 and 11.08%, respectively.